In the past, diverse techniques have been devised as a method for correcting the colors of an image projected by a projector. For example, a proposal was made of a method for correcting the color components of an input image using the spectral reflectance of the plane of projection or the information about the colors under a light source (e.g., see PTL 1). Also, a proposal was made of a method for color correction involving conversion of spectroscopy data to XYZ space in RGB components while correction information is being generated (e.g., see PTL 2).